Rohm and Haas has acquired South Korea's Gracel Display for $40 million. The eight-year-old firm has about 55 employees who develop and manufacture organic light-emitting diode materials. Rohm and Haas says it has invested more than $270 million over the past 12 months to build a flat-panel display technologies business. Separately, the Philadelphia-based company has agreed to sell its 40% stake in South Korea's UP Chemical for $112 million to a group of South Korean investors. UP is a specialist in dynamic random-access memory and high-k gate dielectric precursor technology used to make semiconductors. Rohm and Haas bought its stake in UP in 1998 for $3.5 million. It continues to be involved in the high-k field through an amidinate compound licensing agreement signed last year with Harvard University.